Microsoft's 'Custom XML' patent suit could put ODF at risk

The infamous U.S. District Court for the Eastern District of Texas has slapped Microsoft with a permanent injunction that "prohibits Microsoft from selling or importing to the United States any Microsoft Word products that have the capability of opening .XML, .DOCX or DOCM files (XML files) containing custom XML," according to CNET. This likely won't stop Microsoft Office from shipping, as CNET's Ina Fried writes, but the bigger question may be whether the lawsuit will reach beyond Redmond to also threaten the Open Document Format (ODF).

The lawsuit doesn't affect all of Microsoft Office, but only Word, and only the "Custom XML" functionality, as ZDNet's Mary Jo Foley highlights. Even so, you can almost hear the cries of jubilation from the open-source community, happy to see Microsoft get a taste of its own patent saber-rattling.

The more I read through the patent claim the less confident I was with my initial reaction. In fact, I think this one might actually have some legs. Keep in mind is that this claim was filed back in 1994. The claim considers the existing state of the art at that time....

One thing seems clear to me - this is not a typical rubbish software patent that earns its filer a 20 year monopoly on the dead obvious. Fifteen years ago this would seem to me to have been an innovative idea....

But, if the validity of the patent is upheld then the immediate question is whether this will also impact ODF. If so, then this turns out to be a significantly more important issue and one which will crystallize the fury of the anti-patentistas. No longer will this be the source of some Schadenfreude at Microsoft's expense. This will be seen as yet another attack on open standards and open software.

It's an interesting question, one to which I don't know the answer, not having reviewed the patent in any detailed form. But it's at least a poignant reminder that the collateral damage in any patent infringement lawsuit could well extend beyond the initial target, in this case hitting the open-source world even as Microsoft is smacked around.

The current version of ODF doesn't include Custom XML-type code, as Redmond Magazine writes, but the next version will. Could this patent suit make momentary friends of Microsoft and the open-source community?

Anyone that can offer color commentary on the patent and ODF in particular?

Update: See Sean Michael Kerner's post, suggesting that two particulars (i4i is not a patent troll and i4i and Microsoft had a business relationship) suggest that the open-source world has little to fear from this suit.